Most digital camcorders record and transmit compressed audio and video data in accordance with the International Electrotechnical Commission (IEC) Standard IEC 61834 for Helical-Scan Digital Video Cassette Recording Systems (the “DV” standard). On the other hand, most home entertainment systems, such as Digital Versatile Disk (DVD) player-recorders, and the like, operate on audio data in either the Moving Picture Expert Group (MPEG) or AC3 audio formats. Hence, in order to for a device or system to be compatible with a both a DV data source, such as a camcorder, and an MPEG or AC3 recording and playback system, such as a DVD player-recorder, some provision must be provided for “transcoding” between the DV and MPEG formats. This transcoding process can be difficult to implement in real-time systems, since the DV data rate is several times higher than the MPEG and AC3 data rates.
In order to mitigate effects such as burst errors, audio data samples recorded in accordance with the DV standard are “shuffled” during the encoding operation using modulo-arithmetic techniques. Therefore, during the DV to MPEG transcoding process, the DV encoded audio samples must be “de-shuffled” such that the proper temporal sequential relationship between data is restored. There are a number of ways in which the de-shuffling operation may be performed; however, most conventional digital signal processor (DSP) de-shuffling techniques require many barrel shifting operations and the utilization of a substantial amount of memory. Furthermore, such conventional techniques require relatively complicated firmware, and do not guarantee transcoding in real-time.
In sum, techniques are required for de-shuffling DV encoded audio samples, which are efficient and may be performed in real-time. Such techniques should be particularly applicable to DV to MPEG transcoding processes, although not necessarily limited thereto.